Version number bumps for iperf-3.15.
diff --git a/RELNOTES.md b/RELNOTES.md
index 8c48cfd..48130e9 100644
--- a/RELNOTES.md
+++ b/RELNOTES.md
@@ -1,6 +1,24 @@
 iperf3 Release Notes
 ====================
 
+iperf-3.15 2023-09-14
+---------------------
+
+* Notable user-visible changes
+
+  * Several bugs that could allow the iperf3 server to hang waiting
+    for input on the control connection has been fixed. ESnet thanks
+    Jorge Sancho Larraz from Canonical for reporting this issue. For
+    more information, see:
+    https://downloads.es.net/pub/iperf/esnet-secadv-2023-0002.txt.asc
+
+  * A bug that caused garbled output with UDP tests on 32-bit hosts
+    has been fixed (PR #1554, PR #1556). This bug was introduced in
+    iperf-3.14.
+
+  * A bug in counting UDP messages has been fixed (PR #1367, PR
+    #1380).
+
 iperf-3.14 2023-07-07
 ---------------------
 
diff --git a/configure.ac b/configure.ac
index fb0721d..1b3c413 100644
--- a/configure.ac
+++ b/configure.ac
@@ -25,7 +25,7 @@
 
 # Initialize the autoconf system for the specified tool, version and mailing list
 AC_PREREQ([2.71])
-AC_INIT([iperf],[3.14],[https://github.com/esnet/iperf],[iperf],[https://software.es.net/iperf/])
+AC_INIT([iperf],[3.15],[https://github.com/esnet/iperf],[iperf],[https://software.es.net/iperf/])
 m4_include([config/ax_check_openssl.m4])
 m4_include([config/iperf_config_static_bin.m4])
 AC_LANG(C)